Abstract: Detecting a discontinuity or impedance irregularity in an active line, a neutral return line and/or an earth return path of a power distribution network is disclosed. In one aspect, the apparatus is configured to measure a change in voltage and/or current associated with a deliberate switching of a known impedance and/or a naturally occurring random switching of an impedance in the electrical network wherein the change in voltage and/or current flow results from a discontinuity or impedance irregularity in the active line, neutral line and/or earth return path. The apparatus includes an algorithm for identifying discontinuity or impedance irregularity in the presence of allowable variation in voltage and/or current that may mimic or hide a discontinuity or impedance irregularity in the active line, neutral return line and/or earth return path including a reverse current flow through the earth return path.

Abstract: A method is disclosed for detecting a discontinuity or irregularity in a supply line of an electrical power distribution network including a neutral return line and an earth return line. The method includes measuring a property associated with the supply line wherein the property is different when the network includes the neutral return line compared to when the network does not include the neutral return line. The method also includes comparing a result of the measuring with a reference to provide an indication of the discontinuity or irregularity. The property may include a complex impedance associated with the neutral return line or earth return line and/or ambient electrical noise present on the supply line. An apparatus for detecting a discontinuity or irregularity in a supply line of an electrical power distribution network is also disclosed.